Abstract: A hob for cutting gear teeth includes a plurality of generally axially extending and generally circumferentially spaced rows of teeth. The hob is adapted to be thrown away instead of being re-sharpened when the cutting edges of the teeth become worn. Consistent with this, the teeth--rather than being formed with a conventional re-sharpenable profile--are ground so that the tip, the side flanks and the root of each tooth are of a circumferentially concave shape. The grinding is effected by a unique positional mode in which the hob blank is held stationary and in which the grinding wheel is located relative to the blank in such a manner as to enable the use of a wheel of the largest possible diameter for the design criteria of the particular hob being formed.